BS 8102:2009-Important New Waterproofing Regulations

BS 8102 is a design document whose purpose is to inform the designer of the various methods of waterproofing available and to assist in the correct specification of those systems. Although other documents are available, BS 8102 is THE document that you should be familiar with. Although not UK law, failure to use BS 8102 could result in the designer having a difficult time in a court of law in the event of litigation following a waterproofing failure. It is almost certain that this code of practice will be used by the prosecuting expert witness.

The New British Standard BS 8102:2009 came into effect 30 November 2009 and supersedes BS 8102:1990

A number of new recent developments are addressed which are important when specifying, designing and constructing below ground structures including:

• More deep construction in urban areas
• The increase in provision of residential basements
• The development of and use of new waterproofing materials

The New Standard And What It Entails

BS8102:2009 highly recommends that a waterproofing specialist is involved from design stage

 The new standard recognises that it is essential for the success of any project involving below ground structures that strategies for dealing with groundwater, soil gases and contaminants are considered from the very earliest stages of the planning and design processes. For new structures it is recommended that the structural design, overall weatherproofing design and construction processes are considered together as they generally interact. In addition it is recommend that during the design process and at all stages of the construction process, the designer’s specialists manufacturers, suppliers and installing contractors establish and maintain effective channels of communication. Regular and clear communication coupled with good site supervision allows variations and amendments to the design to be planned and executed without compromising the performance of the waterproofed structure.

In our experience this “team” approach from design stage allows for successful and cost effective waterproofing and as part of the rewrite committee we were very keen for the this strategy to be emphasised. A welcome inclusion to the standard now asks for waterproofing specialist to be included as an integral part of the design team to ensure that an integrated waterproofing solution is realised. Criteria outlined in the standard are that the individual be:

1. Suitably experienced
2. Be capable of devising solutions that accommodate the various projects constraints and needs
3. Provide the design team with information and guidance that assists with and influences the design, installation and future maintenance of the waterproofed structure

Newton Specialist Basement Contractors

Contact us for a list of Newton Specialist Basement Contractors in your area

Successful waterproofing has always been a specialist’s area of expertise – not for the DIY enthusiast! The key causes of failure in our experience are “poor workmanship”, poor product choice for the level of waterproofing required and cheap inappropriate products substituted from those specified to get inside an unrealistic budget. The inclusion of a waterproofing specialist in the early stages of the waterproofing discussions will ideally design out the above key causes of failure and provide robust and successful waterproofing projects. This company, for this very reason, works with an elite group of fully trained waterproofing contractors, Newton Specialist Basement Contractors (NSBC) who can accommodate for specifiers and end clients the role of “Waterproofing Specialist”. All our registered contractors offer insured guarantees for the installation and the vast majority of NSBC contractors can also offer full PI on waterproofing design and installation giving full protection to all parties concerned.

Principles of BS 8102

Principle considerations are listed in BS8102 in order to develop a robust design for protecting a structure against groundwater. The overall general principle is to assess the risk of water reaching the structure and then to select a waterproofing system capable of achieving the required internal environment. The ideal waterproofing solution would be defect-free. However it should be noted that two types of defect might occur in any waterproofing where a structure is subject to water pressure, and this could mean that the required internal environment is not achieved.

These defect are as follows:

1. Defects owing to poor quality workmanship
2. Defects owing to the specific properties of the materials being used

Newton System 500 is fully compliant with BS8102:2009

It is essential that the construction methods and materials used to realise the design are such that the defects in workmanship are a) are avoided and b) which are generally minor, should be recognised and catered for in the design. Contingency planning for dealing with any localised defects or system failure that arise should be included as part of the overall water resisting design of the structure. In either case it is vitally important to take into account the ability of reparability of the waterproofing system and the feasibility of remedial measures assessed. The ability to repair external systems has changed the way professional waterproofing contractors can now guarantee external waterproofing projects and highlights the practical nature of the type C drained protection option.

Risk Assessment

As a part of the new design standard it is advised to carry out a risk assessment stipulating that the principle risks with respect to water ingress into structures are the external environmental conditions. As a part of the risk assessment it is also suggested to perform a Desk Study in accordance with BS 5930 and BS EN1997:

1. To assess the geology and hydrogeology , including soil permeability, flood risk, radon, methane and other ground gases and contaminates. (e.g. chlorides and acids)
2. To assess the topography of the surrounding ground in relation to the below ground structure
3. To establish the likely highest level of the water table and the potential for the occurrence of a perched water table; and
4. To identify any missing ground and ground water information which should then be obtained by undertaking a site investigation in accordance with BS59230 and BS EN1997
5. The drainage characteristics for analysis of the soil should be determined in accordance with BS8004

It’s difficult to predict our weather these days!

Other Design Principles

Click here to download Newton's Free Guide: BS8102:2009 Waterproofing Regulations - What Does It Mean To Specifiers

The new standard has many other important design principles for the design team to consider:

Designers are urged to design structures to full head in all earth retaining situations where:

1. No detailed geological or hydro geological assessment has been undertaken
2. The results of the soil investigations are inconclusive with respect to groundwater
3. The ground drainage characteristics are unreliable
4. The drainage measures either internal or external are unreliable or un maintainable and infiltration cannot be controlled

Even with a full site investigation available to you, as a designer you are required to make the design decisions to protect your structure from water from the following sources, not just underlying water tables:

1. The inflow of surface water, ranging from percolation of rain to inundation of water from burst water mains
2. The water pressures acting on the external retaining wall system
3. The water pressures below the slab base

It is also noted that water resisting design should enable the system to withstand a pre-determined head of water or control the water before it reaches the structure. In a worst case scenario, designers have to account for full head of pressure at some point in the structures life and that the system installed is robust enough to manage the potential ingress, taking into account that defects may be present in the application of the waterproofing system.

In Conclusion

Newtons offer a CPD about the implications of BS8102

To sum up, the British Standard has been upgraded to include the new technologies available to waterproofing designers, and the suggested “packaged” waterproofing design involving a qualified design team has addressed the previous issues which resulted in many failures of waterproofing systems, namely poor workmanship and poor choice of materials. These changes allow for manufacturers, specifiers and end clients a “peace of mind” that waterproofing can be performed constantly to a managed high standard so that as the use of basement space becomes more and more popular, the correct combination of materials and planning is available to get it done correctly the first time.

For a full analysis of how BS 8102:2009 please contact John Newton who can give double points RIBA approved CPD on the topic, or fillout our Book CPD Online Form

Warren Muschialli
Director

This entry was posted in Advice, Basement Waterproofing • June 28th, 2011 • Back To Top

5 Responses to “BS 8102:2009-Important New Waterproofing Regulations”

1. Devinder Chawla says:

   November 20, 2010 at 5:56 am

   Dear Sir,
   We want to use these specs in India.
   We would be keen to attend one of the seminars being conducted by you.
   Can you send seminar information to us in pdf for us to upgrade us and use this information in Industry.
   Regards,
   Er. Devinder chawla

   Reply
   • Lucinda Muschialli says:

     November 20, 2010 at 1:18 pm

     Thank you for your comment, the managing director Warren Muschialli will email you on Monday
     Regards
     Lucinda

     Reply
     • Devinder Chawla says:

       October 18, 2011 at 11:50 am

       We had requested you to send us copy of CPD in Pdf format so that we can upgrade our self as organising CPD in INDIA doesnot seem feasible at this moment.
       awaiting your response.
       Regards,
       Er. Devinder Chawla

       Reply
2. joe delaney says:

   June 21, 2011 at 1:45 pm

   My house as I discovered (6-7 years built) is now letting in water though basement I have found that it does not have any cladding or internal tanking . The house is built on a slope the front level been higher than the back. What should heve been done to pervent this?

   Reply
   • Lucinda Muschialli says:

     June 21, 2011 at 2:39 pm

     Hi Joe, thanks for your comment

     In our opinion the best way to have dealt with this situation is to have installed a maintainable waterproofing system in accordance with BS8102. This would mean a drained cavity system dimpled membrane that would go onto the retaining walls (8mm stud) terminating into a internal basedrain which because you are into a hillside could easily discharge under gravity to the open elevation meaning no need for a sump and pump. External systems are very difficult to maintain. As such the internal system in your circumstance in my opinion would be the easiest option. It is also an option for remediation works now. If we can be of any further assistance please feel to call Newton technical on 0207 2371217. We could also give you a list of registered installers in your area, I notice your web address is .ie, and we have installers in Ireland so do contact us for their details
     Many thanks

     Reply